It is desirable to improve the efficiency of existing refrigeration systems, such as beer coolers, in order to conserve energy. One means of improving the efficiency of refrigeration systems and to conserve energy is to employ outside colder air in the environment, when the temperature of the inside refrigerator area drops below the temperature at which the area is maintained. For example, the desired temperature in a beer cooler is typically about 32.degree. F. to 48.degree. F. Therefore, it would be desirable to employ cold outside air within such a beer cooler when the outside air falls below 48.degree. F.
There have been a number of systems proposed to employ ambient air as an assistant for refrigerating units, such as, for example, as described in U.S. Pat. No. 4,023,947, wherein ambient air is supplied at a controlled rate to a refrigerated enclosure, when the ambient-air temperature drops below that within the enclosure. The described system employs two separate ambient-air supply units, each independently controlled, for operation of different temperature ranges. While such a system employs the cooler ambient air, the system must operate selectively primary and secondary air-supply ducts, and, in addition, operate the refrigeration system continuously. The system is complex and does not provide for adequate control of the air moving between the outside and the interior of the refrigeration system.
A prefabricated kit for an air-conditioning duct also has been proposed (see U.S. Pat. No. 3,946,575), wherein an attachment kit is provided to a return-air duct of an air-conditioning system in a house to employ the colder outside ambient air to aid the air conditioner located within the central duct. This system requires the inclusion of a prefabricated-kit arrangement within a return or by-pass duct in existing air-conditioning systems.
Another system (see U.S. Pat. No. 3,982,583) provides for a variable volume of air by taking fresh air into a building through the air-conditioning system through a sensor for sensing the air in the system and for regulating the airflow to maintain the minimum outdoor air at a level through the use of a damper and sensing means.
It is desirable to provide for a simple, inexpensive, modular, prefabricated, versatile kit to employ efficiently the cooler ambient air to maintain and improve a refrigeration system, such as a beer cooler and the like.